Relation between growth dynamics and the spatial distribution of intrinsic defects in self-assembled colloidal crystal films

Herein we establish a clear relation between the parameters that govern the growth dynamics and the structural quality of colloidal crystal films. We report an optical analysis of the spatial distribution of intrinsic defects in colloidal crystal films and correlate our results with a theoretical model describing the growth dynamics of such lattices. We find that the amount of defects fluctuates periodically and decreases along the growth direction of the lattice. We demonstrate that these spatial variations are a direct consequence of the temporal oscillations of the crystal film formation velocity, which are inherent to the colloidal particle deposition process.Ministerio de Ciencia y Educación MAT2004-0302

Molding with nanoparticle-based one-dimensional photonic crystals: A route to flexible and transferable Bragg mirrors of high dielectric contrast

Self-standing, flexible Bragg mirror films of high refractive index contrast and showing intense and wide Bragg peaks are herein presented. Nanoparticle-based one-dimensional photonic crystals are used as templates to infiltrate a polymer, which provides the multilayer with mechanical stability while preserving the dielectric contrast existing in the mold. Such films can be lifted off the substrate and used to coat another surface of arbitrary shapeMinisterio de Ciencia y Educación MAT2008-02166Junta de Andalucía FQM-357

Towards a full understanding of the growth dynamics and optical response of self-assembled photonic colloidal crystal films

Recent advances in the comprehension of the growth dynamics of colloidal crystal films opens the door to rational design of experiments aiming at fabricating lattices in which the density of intrinsic defects is minimized. Since such imperfections have a dramatic effect on scattered light of wavelength smaller than the lattice constant, the evaluation of the experimental optical response at those energy ranges, based on the comparison to rigorous calculations, is identified as the most sensitive guide to accurately evaluate the progress towards the actual realization of defect-free colloidal crystals.Ministerio de Ciencia y Educación MAT200503028Consejo Superior de Investigaciones Científicas 2005AR007

Interplay between crystal-size and disorder effects in the high-energy optical response of photonic crystal slabs

Experimental reflectance spectra have been obtained for colloidal crystals whose widths ranged from one to several sphere monolayers, and their features in the higher order band energy range have been reproduced theoretically. In order to fit the measured data, optical extinction has been introduced in the theoretical model, which accounts for structure imperfections and disorder, the main sources of losses in an actual measurement. A complex spectrum in the high frequency region is observed even for one ordered monolayer, being this peak structure gradually modified as more layers are piled up. This allowed us to identify which peaks are reminiscent of the optical reflectance features of a single close-packed layer and which are the result of building up a three dimensional periodicity. A clear correlation between the amount of extinction introduced in the fitting and the slab width has been found, which demonstrates that wider real crystals produce less diffusely scattered light. At the same time, we find that the optical response of thinner crystals is more robust against the introduction of extinction than that of thicker ones, for which the effect is dramatic.Consejo Superior de Investigaciones Científicas 2005AR0070Universidad de Buenos Aires ANPCYT-BID 802Agencia Nacional de Promoción Científica y Tecnológica OC-AR03-14099Ministerio de Ciencia y Educación MAT2005-0302

Physical origin of the high energy optical response of three-dimensional photonic crystals

The physical origin of the optical response observed in three-dimensional photonic crystals when the photon wavelength is equal or lower than the lattice parameter still remains unsatisfactorily explained and is the subject of an intense and interesting debate. Herein we demonstrate for the first time that all optical spectra features in this high energy region of photonic crystals arise from electromagnetic resonances within the ordered array, modified by the interplay between these resonances with the opening of diffraction channels, the presence of imperfections and finite size effects. AU these four phenomena are taken into account in our theoretical approach to the problem, which allows us to provide a full description of the observed optical response based on fundamental phenomena as well as to attain fair fittings of experimental results.Consejo Superior de Investigaciones Científicas 2005AR0070Universidad de Buenos Aires ANPCYT-BID 802Agencia Nacional de Promoción Científica y Tecnológica OC-AR03-14099Ministerio de Ciencia y Educación MAT2005-0302

Attention!, your movement makes the city: Choreo-graphic proposals for urban spaces

Within the communicative possibilities of graphics, we focus on the challenge proposed by choreographic notation. This practice combines the technical, the artistic and the semiotic in an attempt to retain the volatility of gesture.  To address this choreographic relationship, we study public art pieces that rely on graphic language to reach the users of urban space. These allow us to identify which elements, common in the context of the city, are recovered from a choreographic vision to activate citizens' reflection and attention and to propose new uses for the spaces they pass through. In recent decades, dance and movement have gained a place in public space through institutional mediation. In response to this reality, we seek to understand how graphics is proposed as a mediating language between cultural spaces and the dwellers of the city.; Dentro de las posibilidades comunicativas de la gráfica, nos centramos en el desafío que propone la notación coreográfica. Esta práctica combina lo técnico, lo artístico y lo semiótico en un intento de conservar la volatilidad del gesto.  Para abordar esta relación coreo-gráfica, estudiamos piezas de arte público que se apoyan en el lenguaje gráfico para llegar a los usuarios del espacio urbano. Éstas nos permiten identificar qué elementos, comunes en el contexto de la ciudad, son recuperados desde una visión coreográfica para activar la reflexión y la atención de los ciudadanos y proponerles nuevos usos para los espacios que transitan. En las últimas décadas, la danza y el movimiento han ganado un lugar en el espacio público a través de la mediación institucional. En respuesta a esta realidad, buscamos entender cómo la gráfica se ofrece como lenguaje mediador entre los espacios culturales y los habitantes de la ciudad

Research and creations between art-architecture to enhance the urban heritage through an educational process

En esta contribución se describe un proyecto de investigación-acción, cuyo resultado fue la produc-ción industrial de un kit (500 piezas) de interpretación del patrimonio cultural basado en la contaminación de diferentes disciplinas. El objeto de la investigación fueron los métodos de mediación e interpretación del patrimonio para activar un proceso de co-construcción con todas las partes involucradas. Los nuevos conocimientos obtenidos se convirtieron en el contenido del kit, para lograrlo fue necesario activar la cola-boración entre las disciplinas, los investigadores y los profesionales. A partir del cambio de paradigma de fruición del patrimonio que normalmente ve al objeto cultural como protagonista y a la comunidad como receptora, se mostrará que el diálogo interdisciplinar ha creado un círculo virtuoso entre la comunidad, el patrimonio y los nuevos receptores de esta acción. En particular, mostrará cómo ha habido un intercambio provechoso entre la educación corporal (expresión corporal), sonora, visual y la educación al patrimonio cultural y de los valores arquitectónicos y urbanísticos del Renacimiento.; This contribution describes an action research project, the result of which was the industrial production of a cultural heritage interpretation 500 kit based on the contamination of languages and disciplines. The object of the research was the methods of mediation and interpretation of heritage to activate a process of co-construction with all traceable stakeholders. The new traced knowledge became the contents of the kit, reaching which it was necessary to establish collaboration between disciplines, researchers and practitioners. Starting from the change in the paradigm of heritage fruition that generally sees the cultural object as a protagonist and the community as a recipient, it will be shown how interdisciplinary dialogue has created a virtuous circle between community, heritage and new recipients of fruitive action. In particular, it will show how there has been a profitable exchange between body, sound and vision education and education in cultural heritage and Renaissance urban architectural values

Design and Realization of a Novel Optically Disordered Material: A Demonstration of a Mie Glass

Herein, a diffusive material presenting optical disorder is introduced, which represents an example of a Mie glass. Comprising spherical crystalline TiO nanoparticles randomly dispersed in a mesoporous TiO matrix, it is proved that the scattering of light in this inhomogeneous solid can be predicted in an unprecedented manner from single-particle considerations employing Mie theory. To that aim, a study of the dependence of the key parameters employed is performed to describe light propagation in random media, i.e., the scattering mean free path and the transport mean free path, as a function of the size and concentration of the spherical inclusions based on a comparison between experimental results and analytical calculations. It is also demonstrated that Mie glasses enable enhanced fluorescence intensity due to a combined absorptance enhancement of the excitation light combined with an improved outcoupling of the emitted light. The method offers the possibility to perform a deterministic design for the realization of a light diffuser with tailor-made scattering properties.European Union 307081Ministerio de Economía y Competitividad MAT2014-54852-

Plan de mejoramiento del sistema de costos de la empresa Carrero & Asociados del sector de servicios y consultorías contables

Carrero & Asociados es una compañía dedicada a la consultoría contable, tributaria, legal y aplicación de las normas internacionales de información financiera (NIIF), también presta el servicio de nómina, lleva 10 años en el mercado y su oficina principal está ubicada en el sector del Salitre en Bogotá. La compañía ha venido creciendo en los últimos años por lo cual sigue en busca de una mejora en la generación de información, es por esto que desea implementar un sistema de costeo eficiente para generar una información confiable

Symmetry analysis of the numerical instabilities in the transfer matrix method

This paper discusses the numerical exponential instability of the transfer matrix method (TMM) in the framework of the symmetry formalism. This numerical weakness is attributed to a series of increasingly extreme exponentials that appear in the TMM when it is applied to geometries involving total internal reflection (TIR) or very high absorption. We design a TMM formalism that identifies the internal symmetries of the multilayer geometry. These symmetries suggest particular transformations of a reference system in the TMM that improve its ill-conditioned exponentials. To illustrate the numerical improvements, we present examples with calculations of electric fields.Nordic Innovation Center 09053Ministerio de Economía y Competitividad MAT2011-23593, CSD2007-00007Junta de Andalucía FQM- 3579, FQM-524